So, operating at elevations above13,000 ft and up to 15,000 takes its toll on one's functioning ability. Despite taking a med to prevent altitude sickness my O2 saturation level dropped to 53% (not good). My heart rate was120 to compensate for lack of oxygen.....I felt a bit tired, dizzy and nauseated.....had that before while climbing mt Adams. One of the team Drs brought a portable hyperbaric bag. He 'strongly urged' me to get in and "decend" a couple thousand feet. After getting in, zippering up the bag and the Dr pumping up the bag for10 minutes my O2 Sat climbed up to89% and I felt great. Plus it was a good parlor trick. These picts are later in the trip tho demo the HBB to other team members.